Twitter provides a "user_mentions" collection of "entities" in the response that you can use for the mentions, along with an "in_reply_to_user_id" element. Those might be what you're looking for.

(NodeXL doesn't use "user_mentions" or "in_reply_to_user_id," partly for historical reasons. Instead, it looks at the "text" element in the response, which is the tweet text, and manually parses it to pull out any mentions and
replies-to in the tweet.)

If that doesn't answer your question, please clarify what it is you're asking for.

The caption on FIGURE 10.17 of the book Analyzing social media networks with NodeXL: Insights from a connected world reads:

"The @vlad43210 1.5-degree egocentric Twitter net- work. Greener vertices have higher eigenvector centrality, and larger vertices have higher betweenness centrality. Thicker edges correspond to users that @reply to @vlad43210 or mention his username in
one of their tweets."